Slump test is the simplest workability find out method or consistency find out method

for concrete.Slump method may be done at the construction site or
laboratory.Concrete slump test is carried at construction site for each
batch because to maintain the uniform quality of concrete for all the batches.This is empirical test measure the workability of concrete.Slump test is the very very low expansive method of finding
workability of fresh concrete also its provide the result immediately

Due to this reason slump test is used all over the world to
find the workability or consistency of concrete

Slump test is proceed as per procedure mentioned in ASTM
C143 united states is 1199 -1959 in india

Slump test is carried in construction field generally to
find out the workability of concrete

Many factors like
water cement ratio, material quality cement quality, aggregate size and shapes
are affected the slump value.In this test maximum aggregate size does not exceed 38 mm

Apparatus required

1 slump cone

2. tamping rod (size 60 mm long 16 mm dia)

3.non porous base plate

4.measuring scale

About slump cone

Slump cone has 30 cm height ,20 cm bottom diameter,10 cm top
diameter

Both side handle is provided to lift the cone vertically

Procedure for slump cone test

1.first clean the inner surface of the slump cone and apply
the oil

2.place the slump cone on the non porous steel base plate

3.take the sample and fill with in the slump cone with four
layer

4.each layer have equal height and tamp each layer with 25 strokes
with the use of tamping rod

5.remove the excess concrete from the top surface and level
the surface with trowel

6.clean cement leaked outer surface of the slump cone

7.raising the mold slowly and carefully immediately in
vertical direction

8.measure the slump value as difference between the slump
height to the tested concrete specimen height that is the slump value

9.keep in mind slump testing place carried out free from
vibration because it affect the exact slump value

Measurement of slump

The slump value is take in term of mm

Types of slump

The shapes of the slump concrete specimen is varied in three
shapes

1. true slump

2.shear slump

3.collapse slump

True slump

True slump is measure in the test slump of the concrete is distance
between top of the concrete and top of the slump cone

Shear slump

Shear slump indicate the slump value is not find out and the
sample is to be retested

Collapsed slump

Collapsed slump indicate the high workability of concrete or
high level wet concrete .it may affect the concrete strength

Recommended slump value for various types of concrete works

s.no

Structures

Slump
value

1

Mass concrete works

25-50 mm

2

Deck slab in bridge

30- 75 mm

3

Vibrated concrete

12- 25 mm

4

pavements

20-30 mm

5

Beam and slab

50-100 mm

6

Column retaining wall

75- 150 m

Application of slump test

1.the slump test is used to maintained the uniform quality
of concrete in different batches

2 simplest method so its made any place and any time

3.low and high slump value warning to the patch operator to
maintain water level